This invention relates to a process for preparing foamed, bioabsorbable polymer particles, e.g., spheroidal particulates or beads, employing a freeze-dry operation. The particles are useful, inter alia, in medical diagnostic procedures such as mammography and in the repair of damaged or defective bone.
The medical use of polymer particles including those of the bioabsorbable variety are known, inter alia, from U.S. Pat. Nos. 3,882,858; 4,535,485; 4,547,390; 4,643,735; and, 4,663,447. There has been an increase in interest in utilizing bioabsorbable polymer particles to facilitate bone or fibrous tissue repair/reconstruction. The particles can be readily conformed to the shape of defects present in bone or fibrous tissue. Additionally, bioabsorbable polymer particles serve as excellent vehicles for the delivery of drugs, growth factors and/or other biologically active substances to surrounding bone or tissue into which the particles are incorporated.